/*****************************************************************************
 * chap.h - Network Challenge Handshake Authentication Protocol header file.
 *
 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
 * portions Copyright (c) 1998 Global Election Systems Inc.
 *
 * The authors hereby grant permission to use, copy, modify, distribute,
 * and license this software and its documentation for any purpose, provided
 * that existing copyright notices are retained in all copies and that this
 * notice and the following disclaimer are included verbatim in any
 * distributions. No written agreement, license, or royalty fee is required
 * for any of the authorized uses.
 *
 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************
 * REVISION HISTORY
 *
 * 03-01-01 Marc Boucher <marc@mbsi.ca>
 *   Ported to lwIP.
 * 97-12-03 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
 *   Original built from BSD network code.
 ******************************************************************************/
/*
 * chap.h - Challenge Handshake Authentication Protocol definitions.
 *
 * Copyright (c) 1993 The Australian National University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the Australian National University.  The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Copyright (c) 1991 Gregory M. Christy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the author.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * $Id: chap.h,v 1.6 2010/01/24 13:19:34 goldsimon Exp $
 */

#ifndef CHAP_H
#define CHAP_H

/* Code + ID + length */
#define CHAP_HEADERLEN 4

/*
 * CHAP codes.
 */

#define CHAP_DIGEST_MD5 5       /* use MD5 algorithm */
#define MD5_SIGNATURE_SIZE 16   /* 16 bytes in a MD5 message digest */
#define CHAP_MICROSOFT 0x80     /* use Microsoft-compatible alg. */
#define MS_CHAP_RESPONSE_LEN 49 /* Response length for MS-CHAP */

#define CHAP_CHALLENGE 1
#define CHAP_RESPONSE 2
#define CHAP_SUCCESS 3
#define CHAP_FAILURE 4

/*
 *  Challenge lengths (for challenges we send) and other limits.
 */
#define MIN_CHALLENGE_LENGTH 32
#define MAX_CHALLENGE_LENGTH 64
#define MAX_RESPONSE_LENGTH 64 /* sufficient for MD5 or MS-CHAP */

/*
 * Each interface is described by a chap structure.
 */

typedef struct chap_state {
	int    unit;                            /* Interface unit number */
	int    clientstate;                     /* Client state */
	int    serverstate;                     /* Server state */
	u_char challenge[MAX_CHALLENGE_LENGTH]; /* last challenge string sent */
	u_char chal_len;                        /* challenge length */
	u_char chal_id;                         /* ID of last challenge */
	u_char chal_type;                       /* hash algorithm for challenges */
	u_char id;                              /* Current id */
	char * chal_name;                       /* Our name to use with challenge */
	int    chal_interval;                   /* Time until we challenge peer again */
	int    timeouttime;                     /* Timeout time in seconds */
	int    max_transmits;                   /* Maximum # of challenge transmissions */
	int    chal_transmits;                  /* Number of transmissions of challenge */
	int    resp_transmits;                  /* Number of transmissions of response */
	u_char response[MAX_RESPONSE_LENGTH];   /* Response to send */
	u_char resp_length;                     /* length of response */
	u_char resp_id;                         /* ID for response messages */
	u_char resp_type;                       /* hash algorithm for responses */
	char * resp_name;                       /* Our name to send with response */
} chap_state;

/*
 * Client (peer) states.
 */
#define CHAPCS_INITIAL 0  /* Lower layer down, not opened */
#define CHAPCS_CLOSED 1   /* Lower layer up, not opened */
#define CHAPCS_PENDING 2  /* Auth us to peer when lower up */
#define CHAPCS_LISTEN 3   /* Listening for a challenge */
#define CHAPCS_RESPONSE 4 /* Sent response, waiting for status */
#define CHAPCS_OPEN 5     /* We've received Success */

/*
 * Server (authenticator) states.
 */
#define CHAPSS_INITIAL 0      /* Lower layer down, not opened */
#define CHAPSS_CLOSED 1       /* Lower layer up, not opened */
#define CHAPSS_PENDING 2      /* Auth peer when lower up */
#define CHAPSS_INITIAL_CHAL 3 /* We've sent the first challenge */
#define CHAPSS_OPEN 4         /* We've sent a Success msg */
#define CHAPSS_RECHALLENGE 5  /* We've sent another challenge */
#define CHAPSS_BADAUTH 6      /* We've sent a Failure msg */

extern chap_state chap[];

void ChapAuthWithPeer(int, char *, u_char);
void ChapAuthPeer(int, char *, u_char);

extern struct protent chap_protent;

#endif /* CHAP_H */
